Deep well drilling jar

ABSTRACT

A jar especially designed for deep well drilling and which automatically retracts the splines into deeply meshed relation while the jar is being subjected to maximum torque while drilling. The spline device, the hydraulic jar device and the hydraulic spline retraction device are sequentially arranged and independently lubricated, while being ruggedly interconnected.

United States Patent 1 Sutliff et a].

1 DEEP WELL DRILLING JAR [76] Inventors: Wayne N. Sutliff; Jim Downen, both of 2931 Pierce Rd, Bakersfield,

Calif. 93308 22 Filed: Apr. 4, 1974 21 App]. No.: 457,772

[52] C5. C1. 175/297 [51] Int. Cl. E218 l/10 [58] Field of Search 175/296, 297, 321

[56] References Cited UNITED STATES PATENTS 2.710.171 6/1955 Baguell 175/297 2.799.478 711957 Kammerer, Jr. 175/321 1 June 17, 1975 3,302,736 2/l967 Kisling 175/297 Primary Examiner-James A. Leppink Attorney, Agent, or Firm-Dana E. Keech 7 Claims, 16 Drawing Figures PATENTEDJUN 17 1975 \yma SHEET DEEP WELL DRILLING JAR SUMMARY OF THE INVENTION Hydraulic jars employed in deep well drilling have heretofore been subject to heavy spline wear not infrequently requiring the jar to be prematurely replaced. This deficiency has been attributed to the tendency of the splines of the jar to become extended as the drill string is lifted and lowered in adjusting downward pressure on the drill while boring.

It is a major object of the invention to eliminate the aforesaid deficiency by automatically locking the spline device of the jar in retracted position as the drill string rises so as to prevent the formation of slack in the jar during transmission of high torque through the jar to the drill.

Another object is to provide such a deep well drilling jar embodying three sequentially arranged independently lubricated devices. to wit: a spline device, a hydraulic jar device and a spline retraction device.

A further object is to provide such a jar wherein said spline retraction device is powered hydraulically by the drilling liquid being delivered under high pressure through the jar to the drill.

An additional object of the invention is to provide such a jar wherein the spline device employs a split wear and retainer sleeve and a split packing retainer ring. and an annular packer at the lower end of the device for assembling and sealing off the male and female spline subs for independently lubricating the same and constituting a safety device to keep the spline device from coming apart should the internal mandrel part at a point above the male spline thus facilitating recovery of the jar.

Yet another object of the invention is the provision of such a jar embodying a hydraulic dash pot sleeve divided into two separate tandem sections, one of which is relatively short and bears a flat radial sealing face on its upper end and a helical score on its periphery, producing a restricted liquid flow passage by-passing said sleeve during a jarring operation, said short section being the wear bearing portion of the sleeve and inexpensively replaceable in the jar when overhauling the same.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 6 inclusive are half vertical sectional views of consecutive portions of a preferred embodiment of the jar of the invention with the parts thereof fully extended as at the moment of striking a jarring blow.

FIG. 7 is a full cross sectional view taken on the line 7-7 of FIG. 6.

FIG. 8 is a full cross sectional view taken on the line 8-8 of FIG. 5.

FIGS. 9 to 14 inclusive are views similar respectively to FIGS. 1 to 6 inclusive with the parts of the invention fully retracted as when drilling.

FIG. 15 is a longitudinal view partly in section and partly in elevation of the hydraulic jarring device of the invention.

FIG. 16 is a cross sectional view taken on the line 16-16 of FIG. 15, and illustrating the relatively free and relatively retarded liquid passages of the jarring device of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of illustration, the invention is disclosed herein as embodied in a deep well drilling hydraulic jar 25 which includes an external tubular mandrel 26 and an internal tubular mandrel 27 which are telescopically related to each other for relative axial movement in the operation of the jar. As shown in FIGS. 1 to 6 inclusive, the external mandrel 26 forms a sleeve which houses the jar and is internally threaded at its upper end so as to screw onto an upper jar sub 28 which in turn is adapted to screw onto the lower pin 29 of a tubular drill string 30 on which the jar 25 is suspended.

The lower end portion of upper sub 28 has an axial bore 31 having an annular groove near its lower end for receiving an O-ring 32. The lower end of sub 28 is also tapered and threaded to form a pin end 33 onto which is screwed the upper end of a heavy tubular section 34 of the mandrel 26 which forms the outer cylinder of a retraction device 35. The cylinder 34 has an axial bore 36 and an ambient liquid radial passage 37 is formed therein just below the pin end 33 of sub 28 which pin end constitutes the upper cylinder head of the device 35. The lower end of outer cylinder 34 is upset inwardly and externally tapered and threaded to form a pin end 40 having an axial bore 41 and counterbore 42, said bore being annularly recessed to receive O-rings 43. The bores 31 and 41 are concentric and equal in radius. A heavy tubular sleeve 44 which is internally threaded at 45 at its upper end screws onto pin 40 and has an ambient liquid radial aperture 46 a short distance below pin 40. The lower end of sleeve 44 is upset inwardly and externally tapered and threaded to form a pin 47 onto which-is screwed the internally threaded upper end of hammer sleeve 48 which comprises the outer cylinder of a jarring device 49 of the jar 25. The sleeve 48 has a smooth cylindrical bore 50 and, at its lower end, a counterbore which terminates in an inwardly upset lower portion of said sleeve comprising a hammer 56 having an axial bore 57 which is annularly recessed to receive an O-ring 58. The hammer 56 is provided with external threads 59 onto which is screwed the internally threaded upper end portion of a heavy sleeve 60 having ambient liquid passages 61 formed radially therein. The sleeve 60 has a bore 62, a lower end portion of which is provided with an annular recess for receiving an O-ring 63. A lower end portion of sleeve 60 is externally recessed and threaded and the matching internally threaded upper end of a female sub 64 of a spline device 65 of the jar 25 is screwed thereto. The lower end portion of sub 64 is externally recessed and threaded and a spline device assembly collar is screwed thereto.

Extending radially inwardly from female spline sub 64 are equally radially spaced female splines 71. Trapped in place by spline device assembly collar 70 when the latter is screwed onto sub 64, is a split retaining sleeve 72 having an annular flange 73 which the collar 70 overlies so as to prevent endwise movement of sleeve 72. The split sleeve 72 is preferably made in two halves, which when assembled, form a bore 74. Just inside its lower end, the collar 70 is provided with an internal annular slot 75 for receiving a split-spring ring 76, the function of which is to retain a divided ring 77 and packing ring 78 confined within the collar 70 and compressed against the lower end of the split retaining sleeve 72.

The female spline sub 64 is provided with suitable tapped holes located near opposite ends of the female splines 71 for filling the space within spline device with a lubricant, these holes then being closed by threaded plugs 79 and 80.

Referring now specifically to the internal tubular mandrel 27, this includes, at its upper end, a pair of thin tubular sleeves and 86 of equal thickness and diameter placed in abutting relation with their abutting ends externally threaded and screwed into an internally threaded piston ring 87 which is slideable in bore 36 and is externally grooved to receive O-rings 88. The sleeves 85 and 86 make a smooth sliding fit with bores 31 and 41 and a sealing engagement with O-rings 32 and 43.

The lower end of sleeve 86 is externally threaded and screws into the internally recessed and tapped upper end of a heavy anvil sleeve 89 of the jarring device 49. This anvil sleeve has a smooth cylindrical external surface 90 which is turned down slightly at 91 near its upper end to facilitate the assembly of the jar. The space between the surface 90 and bore 50 of hammer sleeve 48 is slideably occupied by an annular seal 92 which is recessed internally and externally to receive O-rings 93 and 94.

Formed externally on anvil sleeve 89 at the lower edge of external surface 90 are raised threads 95 and an external groove for mounting an Oring 100. Screwed onto the threads 95 is a valve stop sleeve 101 which makes sealing engagement with O-ring and has a ground radial sealing face 102 on its lower end. Spaced downwardly from face 102 on anvil sleeve 89 and formed outwardly therefrom is an annular anvil 103. The outer surface of sleeve 89 between sealing face 102 and anvil 103 is dressed down to give this portion of said sleeve 21 substantially hexagonal shape as shown in FIG. 16. Below the anvil 103, the anvil sleeve 89 has a cylindrical external surface 104 which slideably fits within the bore 57 of the hammer 56 and makes a tight sealing fit with O-ring 58. The lower end portion of sleeve 89 is provided with external tapered threads 105 which screw into matching internal threads provided in the upper end of male spline sub 106, an upper end portion of which has a smooth cylindrical outer surface 107 which is slideably received in bore 62 and makes a sealing engagement with O-ring 63. The smooth external surface 107 of sub 106 extends downwardly to the upper end of a series of male splines 108, formed outwardly from said surface. The lower ends of said splines terminate as shown in FIG. 6 (with the jar 25 in its maximum extended condition) a short distance above split retaining sleeve 72. g

The smooth outer surface 107 of the male spline sub 106 is resumed below the lower ends of splines 108 and makes a smooth sliding fit within bore 74 of split retaining sleeve 72, packing ring 78 and divided metal ring 77. The smooth surface 107 then continues downwardly a distance slightly in excess of the distancetelescopic movement is provided for between the two mandrels of the jar, which in the present jar is preferably nine inches, sub 106 there integrally merging with a sub 109 having a threaded tapered pin 110 which unites this with a drill 115.

A radial aperture 116 is provided in sleeve 86 just below piston 87 so as to transmit fluid under pressure traveling throughjar 25 to the drill from the inside of sleeve 86 into the space 117 confined beneath piston 87 in outer cylinder 34 for a purpose to be made clear hereinafter.

Fitting within the annular recess formed externally in anvil sleeve 89 between stop sleeve 101 and anvil 103 is a sectional valve sleeve 118 made up of tandem valve sections 119 and 120. Valve section 119 is the wear section, the upper end of which is provided with a ground radial sealing face 121 which makes a tight sealing fit with sealing face 102 on the lower end of the stop sleeve 101. Both sections 119 and of the sectional valve sleeve 118 are externally finished to make a close sliding fit within the bore 50 of hammer sleeve 48. As shown in FIG. 16, the sectional valve sleeve 118 also slideably fits over the hexagonal shaped section 122 of anvil sleeve 89 leaving six relatively large passageways 123 extending from annular anvil 103 to stop sleeve 101 (see FIGS. 4 and 11) so that whenever in the operation of the jar 25 the sleeve 118 is caused to move downward away from stop sleeve 101 towards anvil 103, a free passage is provided by passageways 123 for operating liquid to flow downwardly past the valve sleeve 118.

The operation of the jarring device 49 requires the provision of a relatively slow-liquid escape passage in the sleeve 118 and this is provided in the present invention by forming a helical score 124 in the periphery of wear section 119 of the valve sleeve. This score allows liquid under the high pressure developed in the jar 25 to bypass the valve sleeve 118 at a fairly slow rate giving the dash pot action required in a deep well jar. When, on the other hand, the sleeve 118 shifts downwardly relative to the internal mandrel so as to come to rest on the anvil 103, notches 125 provided in the lower edge of main sleeve section 120 allow for the free flow of operating liquid into and from the large passages 123 so as to allow said liquid to freely bypass the sleeve 118 to facilitate the proper operation of the jar device.

OPERATION While the jar 25, suspended on the lower end of drill string 30, is being lowered into a well for the purpose of getting ready to perform a well boring operation and with the drill suspended on the lower end of the jar, the various elements of the internal mandrel 27 of the jar hang downwardly as shown in FIGS. 1 to 6 inclusive. All such drilling operations require the circulation of drilling liquid, generally a light mud, downwardly through the string and the jar and the drill and outwardly into the hole at the point where the drill is working. The liquid pressures developed in these drilling operations run sometimes as high as 3,000 pounds to the square inch. The present invention makes use of this liquid pressure to lock the elements of the jar in retracted relation so as to present said elements in their strongest. inter-relation for withstanding the strains imposed in well drilling operations on any jar assembled.

with the drill in the string. This is particularly helpful with respect to the spline device of the jar which functions to transmit torque to the drill and thus suffers particularly excessive strains incidental to the drill striking obstacles to its rotation having a tendency to twist the drill off or separate the jar. To effect this purpose, the jar 25 is equipped with the retraction device 35 above described which operates in the following manner:

Upon the introduction of rotary mud or any other suitable drilling liquid into the drill string 30 and applying drilling pressures thereto as aforesaid. this drilling fluid has access to apertures 116 in sleeve 86 and the high pressure of this fluid, which is greatly in excess of ambient pressures present outside the drill string, is directed against the bottom face of the annular piston 87 so as to lift the internal mandrel 27 of the jar into its maximum upward retracted position in which it is shown in FIGS. 9 to 14 inclusive. As thus retracted. the various parts of the jar, and particularly those in the spline device 65, support each other with much greater effectiveness than when extended. By virtue of this action of the retraction device 35, the only time the parts of the jar 25 will be allowed to be extended as shown in FIGS. 1 to 6 inclusive. will be when an occasion should occur in which it will be necessary to use the jar in a jarring operation to dislodge the drill when the latter has become stuck in the well. When this occurs, of course. the pressure of the circulating fluid can be relaxed so that the pressure inside the jar will be equal to the ambient pressure so that there will be no net upward pressure on the piston 87 which would cause the retraction of the parts of the jar.

The claims are:

1. In a deep well drilling jar. the combination of:

internal and external tubular mandrels telescopically related;

means for connecting the top end of one mandrel to a drill string and the bottom end of the other mandrel to a drill;

a jarring device embodied within said mandrels including delayed action means for striking an upward blow on the mandrel connected to said drill, said means also limiting said telescopic movement; spline device embodied within said mandrels including male splines formed on said internal mandrel and intermeshing female splines formed on said external mandrel; and spline retraction device embodied with said mandrels, said device being powered hydraulically from drilling liquid transmitted to said drill through said jar and automatically axially contracting the elements of said jar while said drill is being operated under a high liquid pressure to give said spline device maximum effectiveness in transmitting torque to said drill.

2. A combination as recited in claim 1, wherein said spline retraction device includes an annular hydraulic cylinder formed between said mandrels the two ends of which comprise cylinder heads formed by said outer mandrel and are in slideable sealed relation with said inner mandrel;

an annular piston fixed on said inner mandrel and slideable in said cylinder between said cylinder heads, said piston making a sealing fit with said outer mandrel, and wherein aperture means are provided in said inner mandrel just below said piston to admit drilling liquid from said inner mandrel into said cylinder between said piston and said lower head to lift said piston, and wherein aperture means are provided in said outer mandrel just below said upper head to maintain ambient liquid pressure in said cylinder above said piston.

3. A combination as recited in claim 2 wherein said external mandrel connects upwardly to said drill string;

said internal mandrel connects downwardly to said drill, and wherein said retraction device is located in the top end portion of the tool;

said spline device is located in the bottom end portion of the tool, and said jarring device is located between the other two devices.

4. A combination as recited in claim 3 wherein said jarring device is of the hydraulic, sleeve valve tripping type, the parts of which including an operating lubricant occupying an annular lubricant chamber provided between a lower seal fixed on said external mandrel and slideably engaging said internal mandrel, and an upper seal slideably sealingly engaging both mandrels, an ambient pressure chamber being formed between said upper seal and said lower cylinder head, and wherein aperture means are provided in said external mandrel giving access of well liquid to said ambient pressure chamber.

5. A combination as recited in claim 1 wherein said spline device includes a split wear and retainer sleeve; and

a spline device assembly collar screwing onto the lower end of said external mandrel to enclose and trap said retainer sleeve with said retainer sleeve in axially abutting relation with said male splines, to keep said spline device from coming apart should the internal mandrel part at a point above said male splines.

6. A combination as recited in claim 5 wherein said spline device includes:

upper and lower annular packers at the upper and lower ends of said device to provide an annular lubricant chamber between said mandrels exclusively for confining said spline device in a lubricant; and

means for trapping said lower annular packer within a lower portion of said assembly collar to make sealing engagement between said collar and said internal mandrel.

7. In a deep well tool, thhe combination of:

internal and external tubular mandrels telescopically related;

means for connecting the top end of one mandrel to a drill string and the bottom end of the other mandrel to a drill bit or the like;

a spline device including: a male spline sub embodied with said internal mandrel and having an outer end portion thereof extending slideably outwardly from within the free end portion of said external mandrel;

an inner end portion of said male spline sub slideably fitting within an adjacent portion of said external mandrel;

male spline means provided on a middle portion of the external surface of said male spline sub;

female spline means provided on said external mandrel and extending inwardly in splined relation with said male spline means; and

means limiting telescopic movement between said mandrels to maintain said male and female spline means in constantly meshed relation,

a spline device assembly collar which screws onto said free end of said external mandrel, said collar having an annular internal recess;

8 split retaining sleeve. said spline device thus being held together by said collar and split sleeve, allowing said device to be recovered in the event of said inner mandrel parting inwardly from said male spline means. 

1. In a deep well drilling jar, the combination of: internal and external tubular mandrels telescopically related; means for connecting the top end of one mandrel to a drill string and the bottom end of the other mandrel to a drill; a jarring device embodied within said mandrels including delayed action means for striking an upward blow on the mandrel connected to said drill, said means also limiting said telescopic movement; a spline device embodied within said mandrels including male splines formed oN said internal mandrel and intermeshing female splines formed on said external mandrel; and a spline retraction device embodied with said mandrels, said device being powered hydraulically from drilling liquid transmitted to said drill through said jar and automatically axially contracting the elements of said jar while said drill is being operated under a high liquid pressure to give said spline device maximum effectiveness in transmitting torque to said drill.
 2. A combination as recited in claim 1, wherein said spline retraction device includes an annular hydraulic cylinder formed between said mandrels the two ends of which comprise cylinder heads formed by said outer mandrel and are in slideable sealed relation with said inner mandrel; an annular piston fixed on said inner mandrel and slideable in said cylinder between said cylinder heads, said piston making a sealing fit with said outer mandrel, and wherein aperture means are provided in said inner mandrel just below said piston to admit drilling liquid from said inner mandrel into said cylinder between said piston and said lower head to lift said piston, and wherein aperture means are provided in said outer mandrel just below said upper head to maintain ambient liquid pressure in said cylinder above said piston.
 3. A combination as recited in claim 2 wherein said external mandrel connects upwardly to said drill string; said internal mandrel connects downwardly to said drill, and wherein said retraction device is located in the top end portion of the tool; said spline device is located in the bottom end portion of the tool, and said jarring device is located between the other two devices.
 4. A combination as recited in claim 3 wherein said jarring device is of the hydraulic, sleeve valve tripping type, the parts of which including an operating lubricant occupying an annular lubricant chamber provided between a lower seal fixed on said external mandrel and slideably engaging said internal mandrel, and an upper seal slideably sealingly engaging both mandrels, an ambient pressure chamber being formed between said upper seal and said lower cylinder head, and wherein aperture means are provided in said external mandrel giving access of well liquid to said ambient pressure chamber.
 5. A combination as recited in claim 1 wherein said spline device includes a split wear and retainer sleeve; and a spline device assembly collar screwing onto the lower end of said external mandrel to enclose and trap said retainer sleeve with said retainer sleeve in axially abutting relation with said male splines, to keep said spline device from coming apart should the internal mandrel part at a point above said male splines.
 6. A combination as recited in claim 5 wherein said spline device includes: upper and lower annular packers at the upper and lower ends of said device to provide an annular lubricant chamber between said mandrels exclusively for confining said spline device in a lubricant; and means for trapping said lower annular packer within a lower portion of said assembly collar to make sealing engagement between said collar and said internal mandrel.
 7. In a deep well tool, thhe combination of: internal and external tubular mandrels telescopically related; means for connecting the top end of one mandrel to a drill string and the bottom end of the other mandrel to a drill bit or the like; a spline device including: a male spline sub embodied with said internal mandrel and having an outer end portion thereof extending slideably outwardly from within the free end portion of said external mandrel; an inner end portion of said male spline sub slideably fitting within an adjacent portion of said external mandrel; male spline means provided on a middle portion of the external surface of said male spline sub; female spline means provided on said external mandrel and extending inwardly in splined relation with said male splIne means; and means limiting telescopic movement between said mandrels to maintain said male and female spline means in constantly meshed relation, a spline device assembly collar which screws onto said free end of said external mandrel, said collar having an annular internal recess; a split retaining sleeve fitting within said collar against the free end of said external mandrel and having an annular external flange which fits within said internal recess of said collar, said male spline sub outer end portion beyond said male spline means making a sliding fit with said split retaining sleeve, said spline device thus being held together by said collar and split sleeve, allowing said device to be recovered in the event of said inner mandrel parting inwardly from said male spline means. 